I created a simulation of 750 bodies between 35 and 50 Au away. This is between Neptunes ( 30.1 Au ) and Plutos orbit . Running the sim for more than 4000 years gives the following picture of the belts dynamics : Represented in red is the change of eccentricity ; green is the evolution of inclination . This belt seems to be poor in resonance patterns as opposite to belts in the neighbourhood of Jupiter However the peaks in the picture correspond with the 5/4 , 4/3, and 3/2 resonances to Neptune . The broad basis of the picture indicates a lot of weaker disturbances due to the other giants is present . It's interesting to see that the bodies near to Neptune tend to change their inclination towards Neptunes inclination .

Yes , the resemblance between the two sims is striking , except for the 2:1 resonance , which is hardly visible . However , when I run the sim for longer time the 2:1 resonance pops up more clearly . Each of the resonances seem to need some time to develop .

The Brazilian astronomer Patryk Sofia Lykawka of Kobe University recently demonstrated that in the presence of a body, with mass between 0.3-0.7 Earth masses, could produce exactly the current distribution of characteristics of the families of TNOs.

This body would have migrated of more internal regions to outter regions by gravitational influence of Jupiter.

In their migration it would have stayed a while in the corresponding region of the Kuiper belt, configuring it with the current caracteristics, and then migrated to more distant regions (between 100-175 AU) which stabilized its orbit and eliminate your influence over TNOs.

It is an interesting proposal that could be reproduced in Gravitty Simulator but I do not know how to make the simulation of the migration of the object.

Tony , this makes me think ...One feature in GravSim which may be worth to implement is the possibility to "launch" a spaceraft from one planet in a given direction with given initial velocity . I know it's possible to create a new body and enter the position and velocity ...but it would be easier to use local parameters such as escape velocity and "direction towards" . Do you think this can be done ?